With the rapid development of lighting technique, illumination may not be confined to allow an illuminated object just to be illuminated, but may be escalated into a technique for enhancing the impression of the object by applying light effect in harmony with the color of the object to the illuminated object. The illuminating device can adaptively adjust the color of irradiating light of the illuminating device according to illuminated objects of different colors, so that the impression of the objects of different colors can all be enhanced. Thus, the illuminating device attracts the attention in the industry.